(1) Field of the Invention
The present invention relates to display devices, and specifically it relates to a technique effective to be adopted to display devices which integrally hold components such as a display panel using a frame member.
(2) Description of the Related Art
Display devices for displaying pictures and images (videos) include liquid crystal display devices using liquid crystal panels. The liquid crystal display panels are display panels each including a first substrate known as a TFT substrate, a second substrate known as a counter substrate, and a liquid crystal material (liquid crystal layer) encapsulated between the first and second substrates.
The liquid crystal display devices each further include, for example, a printed circuit board for inputting picture data signals to picture signal lines of the liquid crystal display panel (TFT substrate), a printed circuit board for inputting scanning signals to scanning signal lines of the liquid crystal display panel (TFT substrate), and a printed circuit board which is generally known as TCON (timing controller) substrate and serve to input control signals to each of the two printed circuit boards, in addition to the liquid crystal display panel. When the liquid crystal display devices are transmissive or semi-transmissive liquid crystal display devices, they each have a light source (backlight) in the rear of the liquid crystal display panel when viewed from a viewer.
In the liquid crystal display devices, respective components such as the liquid crystal display panel, plural printed circuit boards, and a backlight are integrally held by a frame member. The frame member includes, for example, a first frame member and a second frame member. The first frame member is arranged in the rear of the liquid crystal display panel and/or the light source when viewed from a viewer and generally known as a lower frame. The second frame member is arranged in front of the liquid crystal display panel when viewed from a viewer and is generally known as an upper frame.
In the liquid crystal display devices, the lower frame and the upper frame integrally hold the liquid crystal display panel and the light source therebetween. In addition, a supporting member typically made of a resinous molded article is circularly arranged on the outer periphery of the liquid crystal display panel when viewed from a viewer. The upper frame and the supporting member support the liquid crystal display panel by holding the outer periphery of the liquid crystal display panel between them. The lower frame and the supporting member hold the light source and an optical sheet such as a diffuser panel between them. Such an optical sheet is arranged between the liquid crystal display panel and the light source.
The printed circuit board for inputting picture data signals to picture signal lines of the liquid crystal display panel (TFT substrate) includes, for example, plural flexible printed circuit boards, and a rigid printed circuit board for inputting signals such as control signals to the plural flexible printed circuit boards. The flexible printed circuit boards carry driver integrated circuits thereon for generating picture data signals to be inputted into respective picture signal lines. The rigid printed circuit board is mounted to and held by an outer peripheral side of the lower frame or the supporting member.
The printed circuit board for inputting scanning signals to scanning signal lines of the liquid crystal display panel (TFT substrate) includes, for example, plural flexible printed circuit boards, and a rigid printed circuit board for inputting signals such as control signals to the plural flexible printed circuit boards. The flexible printed circuit boards carry driver integrated circuits thereon for generating scanning signals to be inputted into respective scanning signal lines. The rigid printed circuit board herein is also mounted to and held by an outer peripheral side of the lower frame or the supporting member.
The printed circuit board for inputting scanning signals may include the flexible printed circuit boards alone in some recent liquid crystal display devices. In this case, signals such as control signals are inputted into the flexible printed circuit boards, for example, from the printed circuit board for inputting picture data signals through interconnections arranged on the liquid crystal display panel (TFT substrate).
The printed circuit board known as TCON substrate is arranged in the rear of the lower frame when viewed from a viewer and mounted to and held by the bottom face of the lower frame. Interconnections of the TCON substrate are connected with interconnections of the rigid printed circuit board for inputting picture data signals into picture signal lines of the liquid crystal display panel (TFT substrate) typically through flexible print cables (FPCs).
A liquid crystal display device having this configuration is assembled, for example, in the following manner. Initially, components such as a reflector, a light source, and a diffuser are arranged on the lower frame, and the supporting member is then screwed to the lower frame. Next, the liquid crystal display panel bearing, for example, the flexible printed circuit boards and the rigid printed circuit board is arranged on the supporting member, and the rigid printed circuit board is mounted to an outer peripheral side of the supporting member. Interconnections of the rigid printed circuit board mounted to the outer peripheral side of the supporting member are connected through flexible print cables. Next, the upper frame is placed on the liquid crystal display panel, and the upper frame is screwed with the supporting member, or the upper frame is screwed with the lower frame, for example. Finally, the TCON substrate is mounted to the bottom of the lower frame, and, for example, a covering member for protecting the TCON substrate is mounted to the lower frame.